Is it poor attention or ADHD... what's the difference?

First part of a very long conversation between myself and Ricci B on what it means to have ADHD. One of the things that we have seen over the last few years is a lot of people saying they have ADHD because they have issues paying attention and have short attention spans...teachers saying students have ADHD because they can't sit still... but is that really what having ADHD is about.